Hi,
Great Deals, can be found in the Buy / Sell of Seabreeze. - I 68kg, and have a 10m and 6m Switchblade IDS, Got a great deal on Seabreeze 10m kite was still crispy and was less than 3 months old.
The following may be of some help
1) Any kite new or 2nd hand will get trashed by a newbie, so don't be afraid of going 2nd hand. - Destroying a $2200 kite is no fun especially if you are watching your pennies
2) Ensure you get a kite from 2006 - onwards, safety systems are far superior.
3) Bow Kite / C Kite / Foil Kite / SLE are all different types of kites, with different safety systems, and suit different types of riders. - Research this topic well. - Alot of Inflatable riders are using Bow / SLE / Delta, though there is a push now for the purest to go back to C Kites.
4) First kite size for a beginner in your size would be a 10-11m kite. A 12m kite for your first kite size you will find a little large when the winds hit 20 knots, you will struggle, as your confidence levels will be low.
What type of kite do you currently have? As this may suit you, spend a little on repairs may be a logical choice.
Goodluck
KR